Classic two-trains (or buses) problem. The key is recognizing that neither statement alone gives you enough to find the actual travel time, but together they do.
Let D = distance between Eastgate and Westhaven.
Let v_W = speed of the bus leaving Westhaven.
Let v_E = speed of the bus leaving Eastgate.
We want: D / v_W (hours for the Westhaven bus to reach Eastgate).
1. Statement (1): v_E = (2/5) * v_W.
This tells us the ratio of speeds. But we still have two unknowns: D and v_W. No way to find D / v_W without more info. Not sufficient.
2. Statement (2): The buses pass each other 5 hours after departing.
When they meet, they've together covered the full distance D.
So: (v_E + v_W) * 5 = D.
But we don't know v_E or v_W individually, just their combined rate times 5. Not sufficient.
Together: From (1), v_E = (2/5)v_W. Plug into the equation from (2):
((2/5)v_W + v_W) * 5 = D
(7/5)v_W * 5 = D
7 * v_W = D
D / v_W = 7
The Westhaven bus takes 7 hours. Sufficient.
Answer: C.
The trap is thinking Statement (2) is enough because you get a number (5 hours). But that's the time until they meet, not the time for either bus to complete the trip. You need the speed ratio from (1) to figure out what fraction of the journey each bus has done at the meeting point.